#Microtwjc Week 6 – Paper Summary and Discussion Points

The authors examined the effect of probiotics and antibiotics on intestinal homeostasis using a a computer controlled model of the human large intestine. Antibiotic associated diarrhea (AAD) and Clostridium difficile infection (CDI) are complications in broad spectrum antibiotic therapy, probiotics have been suggested to be promising agents in the prevent of AAD and CDI. The authors suggest that mechanistic studies in vivo are difficult to perform due to sampling and ethical difficulties and the model simulates the colon to a high degree. The model is a unique tool as its able to study the stability, release, dissolution, absorption of nutrients, chemicals, bioactive compounds and pharmaceuticals in the gastrointestinal tract. They found that short chain fatty acids, ammonia, branched chain fatty acids and lactate were increased when using probiotic therapy compared to the controls and combination therapy (Clindamycin and probiotics). Probiotics following antibiotic therpay did not help to recover the intestinal microbiota lost during the therapy. The main finding is that the simultaneous application of antibiotics and probiotics stablises the intestinal microbiota. The authors conclude that probiotics could be a resonable strategy to prevent antibiotic associated disturbances of the gastrointestinal tract.

Discussion points

* How do you feel about the application of an in vitro model to study this?

* What other experiments could be performed ?

* Do you think probiotics are useful in this application?

* What other data would be needed to convince you that probiotics work?

* Should we be using the probiotic mixture they described? What could the long term consequences be?

More discussion points:
-what exactly is the set up? What exactly happens with the clindamycin followed by probiotics group? Because the text seems to contradict the diagram
-they talk about keeping the pH constant throughout the experiment wouldn’t e.g. lactate,ammonia change the pH? Or do other things in the gut keep it constant?
-why didn’t they look at the 7 days post clindamycin treatment when the clindamycin was given at the same time as the probiotic/ when clindamicin given alone? They show 14 days worth for only 1 condition
-replicates & stats…???